I have an aftermarket charger because the original charger is no longer made, so I would like to test it’s charging stats (watts, volts, ampere, temperature, etc).

From what I’ve seen, most of the apps on PlayStore aren’t showing proper stats. For example, in “AccuBattery”, when my phone is on, it shows around 4.5W, but when I shut down the screen and immediately open it, it drops from 10W back to 4.5W, which is funny because the charger is rated 18W, and just as it’s claim, it is almost as fast, although a bit slower than the original VOOC 3.0.

In some other apps like “Ampere”, the ampere and volt is shown as zero, and in some, it shows as not charging, but it is clearly charging. Is there any accurate app that works on a hardware level?